window.onload=function () {
    /* 左侧导航区域 */
    var leftSpans = document.getElementById("leftSide").getElementsByTagName("span");
    var leftImg = document.getElementById("leftSide").getElementsByTagName("img");
    var number = -1;
    var leftNativeImgArr = ['./img/house.png', './img/music.png', './img/login.png', './img/register.png', './img/admin.png'];
    var leftImgArr = ['./img/house1.png', './img/music1.png', './img/login1.png', './img/register1.png', './img/admin1.png'];
    getOut();

    function getOut() {
        for (var i = 0; i < leftImg.length; i++) {
            leftImg[i].index = i;
            leftImg[i].onmouseover = function () {
                leftSpans[this.index].style.display = "inline-block";
                leftSpans[this.index].style.left = "55px";
                leftImg[this.index].src = leftImgArr[this.index];
            }
            leftImg[i].onmouseout = function () {
                leftSpans[this.index].style.display = "none";
                leftImg[this.index].src = leftNativeImgArr[this.index];
            }
        }
    }
}